Roman Abramovich will always remember his first season as owner of Chelsea football club for the obvious reason.
His £140 million takeover was one the most significant in 21st century football, and changed the course of the club forever.
But he will be forever wondering why his new club could not win the Premier League title in the 2003-04 season under Claudio Ranieri. The failure ultimately cost the Italian his job, but some would argue there was nothing more he could do.
And that's because "The Invincibles" were in his way.
The likes of Thierry Henry, Patrick Vieira and Robert Pires were in devastating form as Arsenal went unbeaten for the entire season to secure what would be their last Premier League title to date, with Chelsea behind them in second position.
Since then, the rivalry between the two has been fierce. But as Arsenal reached their peak, their success has gone downwards since, while Chelsea have gone on to triumph in two European finals and win the Premier League three times.
And here, we show you some of the ways how the Blues are still way out in front of the Gunners. Be sure to let us know your thoughts and opinions in the comments box below.